GB872698A - Improvements relating to spot welding machines - Google Patents

Abstract

872,698. Welding by pressure. TRIANGLE PRODUCTS Ltd. Sept. 7,1959 [Sept. 13, 1958], No. 29382/58. Class 83 (4). A spot-welding machine comprises a compressible member to propel cooling fluid through conduits in the electrodes and/or their holders when the electrodes are brought together to compress the member, re-separation of the electrodes allowing the member to expand and draw in further fluid. A welder 2 mounted on a bench top 1 has electrode arms 3, 4 with electrode tips 3a, 4a which are brought together by depressing a treadle 5 secured to a block 7 pivoted in a bracket 6. The block has an extension 7a for the swivel connection 8 of a link 9 connected to the movable arm 3 and the block supports a member 10 carrying a padded plate 11. Secured to the underside of the bench is a carrier 13 supporting a compressible rubber bulb 14 in a flexible tube 15 in which are arranged two non-return valves 16, 17, the valve 16 allowing water flow into the bulb from supply pipe 18 and valve 17 allowing expulsion of water to the feed-pipe 19. The latter pipe is connected to conduits in the electrodes; the return water therefrom passing into a tank from which the pipe 18 receives its supply. The return pipe from the electrodes may discharge its water as a spray or over heat-exchange deflectors for cooling. When the treadle is depressed to bring the electrodes together the member 11 deforms the bulb to force water along the pipe 19 and through the electrodes and when the treadle returns the bulb takes up its normal shape and is refilled with water. In a modification the bulb is held between two plates, spring-pressed apart, one fixed to the treadle and the other receiving the foot pressure. The conduits to the upper and lower electrode tips may be in series or parallel. Specification 792,766 is referred to.